you may need to update the bootloader of your Raspberry Pi 4B beforehand (please find more details in the user manual)
If you have Raspberry Pi 4B from rather old batch
which is beyond what the servo could resolve)
Shutdown Raspberry Pi when input voltage below preset threshold
and connectors
Zero2Go Omini: Wide input range, multi-channel power supply for Raspberry Pi iot you may need to updateZero2Go from UUGear is a small Raspberry Pi Zero sized (or pHAT shape) extension board that can work as a smart power supply add on for Raspberry Pi. Zero2Go Omini supports all Raspberry Pi models that have the 40 pin GPIO header, including A+, B+, 2B, 3B, 3B+, 3A+, Zero, Zero W and 4B. Zero2Go has quite wide input range (3. 5V~28V), so it is convenient to power your Raspberry Pi with power bank, Li Po battery pack, solar panel, car battery or